Infusion set and adapter for spectroscopic analysis of pharmaceuticals

ABSTRACT

An infusion set and an intravenous bag adapter constructed of ultraviolet transmissive thermoplastic is used in spectroscopic validation of pharmaceuticals. The described hardware allows for qualitative and quantitative assurance of medications and is used to prevent medication errors. The thermoplastic is transmissive in the range of 240 to 315 nanometers.

FIELD OF THE INVENTION

This invention relates to the spectroscopic analysis of chemicalcompounds. More specifically, the invention relates to an adapter and aninfusion set for use in verifying pharmaceuticals as a means to preventmedication errors. The invention includes a chamber that issubstantially transmissive of ultraviolet radiation that is unaffectedby ambient light in a clinical setting, even with a spectroscopic readerthat functions in an unshielded configuration.

BACKGROUND OF THE INVENTION

The problem of medication errors has been well documented. In U.S. Pat.No. 6,847,899, incorporated here by reference in its entirety, Allgeyerdiscusses these issues. In 2012, a Becton-Dickinson study addressedquantification of the problem: Preventable Adverse Drug Events (ADEs)associated with injectable medications impact more than 1 millionhospitalizations each year, and they increase annual costs to U.S.healthcare payers by $2.7 billion to $5.1 billion. Those costs representan average of $600,000 per hospital each year. The medical professionalliability cost for inpatient ADEs from injectable medication reaches anindustry-wide $300 million to $610 million annually, or as much as$72,000 per hospital. Preventable ADEs are associated with a large rangeof harmful pharmaceuticals, from heparin to morphine. For example, acommon error resulting in fatalities and severe injuries is theso-called 10× error, in which the mistake of a single decimal placeoccurs in compounding or programming an infusion pump. In 2007, thewell-publicized injection of 1,000 times the intended heparin dose tothe newborn twins of celebrity Dennis Quaid highlighted the continuingand long-felt need to control ADEs in clinical settings.

Given the magnitude and seriousness of the ADE problem, there are manyongoing strategies to address and mitigate the risks. Becton-Dickinsonutilizes a vibrational spectroscopic technique, wherein the sensor is incontact with the fluid to be analyzed. See US 20120226446; US20120226447; and, US 20120226448. Approaches utilizing fluorescence,NIR, Raman analysis, and other methods have been developed. Theseostensible improvements have turned out to be unsatisfactory, becausethey are ineffective when used in ambient light, thus requiring somesort of shielding. To exclude ambient light adds complexity and costs toworkflow and hardware requirements. As yet, however, no system ofmedication verification has adequately combined the features ofreliability, accuracy, low cost, simplicity, and ease of use, especiallyin a clinical context where ambient light is unavoidable.

SUMMARY OF THE INVENTION

It is, therefore, an object of the present invention to provide anintravenous bag adapter or an infusion set that can be utilizedreliably, accurately, with a minimum of cost and complexity. It is alsodesirable that the device can be used in a clinical context in ambientlight. In particular, the chamber of the adapter and infusion set istransmissive of ultraviolet (UV) wavelengths. Utilizing spectroscopywith a quartz cuvette and wavelengths between 250-300 nanometers (nm)yields accurate qualitative and quantitative results for the high-riskpharmaceuticals responsible for the majority of adverse drug events anddeaths. Quartz cuvettes, however, are impractical for this applicationdue to their fragility, rigidity, and cost. Polycyclic polyolefin hasroughly 82 percent transmission at 280 nm, compared to 90 percent forquartz. Based on the Beer-Lambert law, dimensional tolerances can berelatively liberal while providing meaningful information regarding drugconcentration in the context of common dosage errors. Therefore, byselection of a significantly UV transmissive moldable thermoplastic, anIV bag adapter or infusion set can be constructed that allows forreliable and inexpensive pharmaceutical verification, so that thecomponents can be disposable.

In order to facilitate and improve medication verification, it is highlydesirable to integrate any new processes into existing workflowprocesses. Currently, any compounded IV bag requires that an infusionset be “spiked” or attached to the bag prior to infusion. By adapting aninfusion set for pharmaceutical verification, the existing workflow isunchanged except for the step of inserting the adapter or infusion setinto the spectrophotometric reader. With the present invention, thisstep can be performed in real time in the pharmacy, in the patient carearea such as a nursing station, or at the point of care. Similarly, anIV bag adapter can be spiked in the pharmacy for verification, a labelthen attached, and the bag sent to where it can be spiked with aconventional infusion set.

UV absorption spectroscopy below 315 nm is accurate with an unshieldedsample. This result occurs because incandescent and fluorescent lightemits no energy below this wavelength while sunlight emissions below 315nm are filtered by atmospheric ozone. Therefore, ambient light such asis found in a pharmacy or patient ward or adjacent to a window has noeffect on pharmaceutical analysis utilizing wavelengths below 315 nm andallows for verification in these environments. Therefore, it isdesirable to have an IV adapter or IV infusion set that can be used witha spectrometer in wavelengths less than 315 nm.

In one embodiment, the present invention comprises an IV bag adapterthat includes a chamber that is substantially transmissive ofultraviolet radiation below about 315 nm.

In another embodiment, the invention comprises an infusion set thatincludes a chamber that is substantially transmissive of ultravioletradiation below about 315 mm. In yet another embodiment the inventionincludes a spectrometer that is insubstantially shielded from ambientlight.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a linear calibration curve for Heparin 50 u/cc at 260nm.

FIG. 2 illustrates an IV bag adapter.

FIG. 3 illustrates the IV infusion set, including drip chamber butwithout the tubing that usually comes with an infusion set.

FIG. 4 illustrates a device with a UV transmissive chamber beinginserted into a spectrometer.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is an IV bag adapter or infusion set with a dripchamber that is substantially transmissive of UV light in a range thatis not affected by ambient lighting in a clinical setting. Both theadapter and the infusion set are designed to be inexpensive anddisposable and molded within a tolerance that gives meaningfulquantitative data regarding drug concentrations.

As an example of one injectable medication, FIG. 1 illustrates a Heparincalibration plot at 260 nm. Concentration in units/ml (U/ml) is plottedagainst absorption units (AU) per centimeter (AU/cm). The plot is storedin the memory of a spectrometer (See FIG. 4) for automated comparison ofa recently compounded preparation. An acceptable variance can beprogrammed into the spectrometer, which in the case of heparin is arealistic level on the order of ±25 percent. Widely divergent samplesthat represent potential ADE's are readily identified due to themagnitude of the discrepancies, preventing harm to patients. FIG. 1shows a 50 u/cc concentration with an AU/cm value of 0.5. A 10-folderror plots a reading of 1.35 AU/cm. Therefore, the frequentlyencountered 10× error would easily be recognized, and the heparin samplewould be rejected when tested. With such testing accuracy, the 1,000×heparin error suffered by the Quaid twins would never recur.

FIG. 2 illustrates an adapter 1 for an IV bag (not shown). Typically, amedication for IV infusion will typically be stored (or individuallycompounded) in a plastic bag in the pharmacy of a hospital. When aphysician orders the medication for a patient, the pharmacy retrieves itfrom storage, or compounds it if necessary, and sends it to thepatient's floor and nursing station for infusion. After an IV bag iscompounded and before being sent to the floor, IV bag adapter 1 issterilely inserted via spike 2 into the receptacle of the IV bag, whichis of the same dimensions of receptacle 4. Adapter chamber 3 is purgedof air and filled by IV fluid bag contents by repetitive squeezing ofthe IV bag and chamber 3 until the chamber is preferably at least halffull. This maneuver, besides preparing the solution for spectroscopictesting, has the additional salutary effect of ensuring the mixing ofthe IV bag's contents. The adapter 1 is then inserted into receptacle orslot 12 of spectroscopy enabled reader 7, FIG. 4 discussed below, andthe fluid is verified as to drug contents and concentration by comparingit to a previously entered physician's order. That the chamber is filledat least half way enables the UV waves to pass through the solution asopposed to air. In other words, reader 7 in FIG. 4 has a “light path” inthe lower half of slot 12. If the fluid is verified, a bar coded labelis printed and affixed to IV bag which contains pertinent informationincluding patient name, drug and concentration, time of admixture,physicians name, etc. In this way, compounding and mislabeling errorsare curtailed. Spike 2 and receptacle 4 can be supplied with a peal-offplastic covering (not shown), which ensures sterility until testing.

FIG. 3 illustrates drip chamber 6 of an infusion set 5 that sits atoptest chamber 3, which is also constructed of substantiallyUV-transmissive material. While conventional thermoplastics—likepolyethylene, polystyrene, and polyurethane—have proven substantiallyUV-transmissive, polycyclic polyolefin has proven to be an idealmaterial when all factors are considered. Infusion set 5 can be used inlieu of IV bag adapter 2, as is often the case in clinical practice. Inthis instance, infusion set 5 with chamber 3 can be placed into thereceptacle of a spectroscopically enabled reader (see FIG. 4) forverification of drug type and concentration. This could take place onthe patient ward if the hospital so chooses, such that in pharmacyverification is omitted. It is noted that adapter or test chamber 3 ofboth the IV bag adapter 1 and IV infusion set 5 are preferably of thesame dimension and the spectroscopically enabled reader is constructedto interact and function with either device such that a reader of asingle design and dimensions can be utilized.

FIG. 4 represents a generic spectroscopic analyzer or spectrometer 7 forreading the fluid contents of adapter or test chamber 3. Once chamber 3has been filled to a minimum level 11 of at least one half from IV bag10, the IV bag adaptor 2 or infusion set 3 can be inserted intoreceptacle or slot 12 of analyzer 7. Controls 8 are utilized to controlanalysis that is monitored on screen 9. The various types of controlswill be known by those of skill in the art, and may include dials,buttons, keyboards, touch screens, and the like, that are part of oroperatively connected to the spectrometer. Analyzer 7 can be networkedwith a computerized physician order entry system, and once verificationhas occurred, a bar coded label (not shown) can be printed and affixedto IV bag 10, which is then distributed to the point of care. Dependingon the preference of the institution, the invention and a verificationsystem can be configured be in numerous ways to decrease medicationerrors. For example: A hospital may want to batch-compound a morphinesolution to be used for filling multiple IV bags for use with patientcontrolled anesthesia pumps. After a hundred bags are filled from themorphine stock preparation, a number of bags may be randomly chosen foranalysis and verification utilizing IV adapter 1. If the verification isconsistent with the purported drug and its specified concentration,those bags can be labeled and sent to the patient care areas for use. Inthis way the drug and concentration is verified and the hospital cansave money by batch-compounding high-risk drugs with assurance. Onceready for infusion at the bedside, the barcode may be read by thebarcode-enabled infusion pump, which also contains an institutionalreference of normal values based on patient weight, age, etc. Should thepre-established institutional norms be exceeded, an alert would bedisplayed and the infusion pump would immediately be locked or stoppedto prevent administration of the incorrect medication. In this manner,errors of compounding or pump programming are discovered and prevented.Other institutions may deploy other strategies for prevention ofmedication errors and or diversion of medications. For example, infusionset 5 can be used at the point of care in a continual surveillance mode.Drip chamber 6 of IV infusion set 5 can be monitored spectroscopicallyin such a fashion by placing it into the receptacle with aspectroscopically enabled sensor. It can then be clamped to the dripchamber or pole mounted and then connected to the infusion pump for realtime monitoring of drug infusion.

What is claimed:
 1. A system for use in spectroscopically testing thecontents of an IV fluid, comprising: a source of IV fluid; a tube havinga first end engageable with the source and a second, distal end; a testchamber for receiving IV fluid from the source and for holding a testsample of the IV fluid, wherein the test chamber comprises a translucentmaterial that is transmissive of ultraviolet light and the test chamberreceives the test sample from the distal end of the tube; a test chamberholder, wherein the holder is substantially unshielded from ambientlight; and, wherein the test chamber and the holder are configured toprovide a fixed, substantially unshielded path for UV light to be usedin the quantitative application of Beer's law.
 2. The invention of claim1, wherein the test chamber is transmissive of ultraviolet light havinga wavelength of about 240-315 nanometers.
 3. The invention of claim 2,wherein the test chamber is comprised of a thermoplastic.
 4. Theinvention of claim 3, wherein the thermoplastic is a polycyclicpolyolefin.
 5. The invention of claim 1, further comprising an IV tubedisposed distal to the test chamber.
 6. The invention of claim 1,further comprising a spike at the first end of the tube.
 7. Theinvention of claim 1, further comprising a drip chamber disposed betweenthe distal end of the tube and the test chamber.
 8. The invention ofclaim 7, further comprising a spike at the first end of the tube.
 9. Theinvention of claim 7, further comprising an IV tube disposed distal tothe test chamber.